US2085796A

US2085796A - Method of making reducers

Info

Publication number: US2085796A
Application number: US48279A
Authority: US
Inventors: Rudolph E Fritsch
Original assignee: TUBE TURNS Inc
Current assignee: TUBE TURNS Inc; TUBE-TURNS Inc
Priority date: 1935-11-05
Filing date: 1935-11-05
Publication date: 1937-07-06
Anticipated expiration: 1954-07-06

Description

July 6, 1937-. R. ELFRlTS C-H METHOD OF MAKING REDUCERS Filed Nov. 5, 1935 INVENTOR IBM 04M zrmzsm BY 0-,...

ATTORNEYS Patented July 6, 1937 UNITED STATES PATENT OFFICE METHOD OF MAKING REDUCERS Rudolph E.,Fritsch, Louisville, Ky., assignor to Tube-Turns, Incorporated, Louisville, Ky., a corporation of Kentucky Application November 5, 1935, Serial No. 48,279

3 Claims.v (01. 29156) The present invention involves a new method of making a novel fiangeless reducer which may be butt welded to pipes of different diameters.

In carrying out my invention I use a standard wrought metal cylindrical pipe section'which mayreducer.

As an important feature of my invention, this pipe section is expanded by afrusto-conical mandrel to frusto-conical form by effecting a relative longitudinal movement of the pipe section and the mandrel disposed therein.

ning the wall.

As a further-feature of my invention, the angle of the surface of the mandrel to the axis thereof, the temperature to which the pipe section is heated, and the rate of endwise movement, are all such in respect to the character 01' the metal employed that the resistance to endwise movement and the resulting tendency to retard the endwise movement and increase the thickness of the wall are counteracted by the expansion of the tube with the resulting tendency toward thin- The conditions are so controlled that the force tending to expand and thin the wall substantially balances the force tending to retard and thicken the wall, and as a result the pipe section is shortened at a rate corresponding to that at which it is expanded and the final product has a wall thickness substantially equal to that of the original pipe section, but is considerably shorter and is tapered from the original diameter at one end to a very much larger diameter at the opposite end.

trated the method by means of which this fitting reducer fit- Fig. '4 shows somewhat diagrammatically an apparatus for carrying out my new method of forming the reducer fitting of Fig. 1.

My improved reducer fitting III as shown in Figs. 1 and 2 is of right frusto-conical shape for connecting -two concentric pipes of diiferent diameters. The fitting has no flanges at its end and is made of wrought metal, so that it may be butt welded to these pipes. The walls are of uniform thickness throughout and preferably of the same thickness as the walls of the pipes. The ends of the fitting are in parallel planes at right angles to the axis and are beveled as at l I so that when it is mounted in welding position coaxial with the pipes to which it is to be connected, the beveled surfaces thereof cooperated with similar beveled surfaces on said pipes to form v-shaped grooves in which the circumferential welds are formed.

In Fig. 3 is shown an eccentric reducer fitting [2 which can be formed from the concentric fitting shown in Fig. 1 by cutting the ends of the latter fitting obliquely with respect to its axis and in parallel planes at right angles to one side. Two pipes 13 and M of different diameters may be 2 alined along one side as for instance on the bottom side as shown in Fig. 3. The fitting l I may be welded to the two pipes while all three parts rest upon a fiat surface. The ends of the reducer and the pipes may bebeveled to form V grooves for the circumferential welds i5, I50.

As an important feature of the present invention, the reducer fitting is formed from a cylindrical pipe section which may be either seamless or welded and which is of the wall thickness desired for the reducer. This cylindrical pipe section is expanded to frusto-co'nical form by eifecting a relative longitudinal movement of the pipe section and a right frusto-conical mandrel. The pipe section is heated during this swaging operation and the temperature and relative movement of the pipe section and the mandrel aresuch that the final product has a wallthickness substantially equal to that of the original pipe section.

In carrying out my new method I provide a right frusto-conical mandrel l6 having the pitch or angularity of the desired reducer and having its opposite ends-at least as large as those of the desired reducer, and having a. length at least as 0 great as said reducer. The reducer is shown as having its smaller end provided with a shank l'l releasably connected to a. mandrel rod 3 connected to the piston in a hydraulic cylinder 20. Either the piston and the mandrel orthe cylinder is held against longitudinal movement. In the form illustrated the cylinder is endwise movable.

-A series of standard cylindrical pipe sections II of wrought metal are strung along the mandrel rod It so that the pipe section at-the right-hand end of the series (Fig. 4) engages a stop rigid with the cylinder. This stop is shown as a plate 22 rigidly connected to and spaced from the head end of the cylinder 20 and movable therewith along the mandrel rod it. These pipe sections,

as they move along the mandrel rod l8, may be held in or brought into alinement with the mandrel shank I! by means of a pair of suitable rollers 23. I

The mandrel I6 is enclosed in a furnace 25 which is shown as open on the side thereof facing the hydraulic press and supported on a portable truck 26. The furnace 25 is heated in any suitable manner as for instance by any suitable number of torches 21.

The mandrel or its shank is detachably connected to the mandrel rod in such a manner as to permit easy and quick connecting and removal. As a conventional showing of such a connecting means, I have illustrated a bayonet joint 30. Screw threads might be used. The con-.

necting and disconnecting may be eflected by engaging a wrench or tool in sockets 3| in the large end of the mandrel.

In carrying out my method, the pipe sections 2| are forced along the mandrel rod l8 by supplying fiuid under pressure to the cylinder to cause the latter to move toward the left as shown in Fig. 4, so that the left-hand end pipe section is forced onto the mandrel l6. Prior to the forcin the pipe section is heated, the temperature and rate of endwise movement being so controlled in respect to the character of the metal employed, and the angle of the mandrel surface, that the resistance to endwise movement and the resulting tendency to increase the: thickness of the wall are counteracted by the expansion of the pipe section with the resultant tendency toward thinning the wall. The expanding and contracting forces are so controlled as to' balance each other so that the final frusto-conical pipe section II! has a wall thickness substantially equal to the original pipe section 2i. It will be noted that the heat in the furnace will ordinarily be greater adjacent to the larger end of the mandrel due to the facility with which the heat 'may escape from the opposite open side. It will also be noted that as the pipe blank is forced endwise into the furnace and along the mandrel until the operation is completed with the parts in the position shown in Fig. 4, the front or advancing end of the pipe section will be in the furnace for a greater length of time than the rear end. Furthermore, the heat will be conducted from the furnace along the shank of the mandrel and the pipe section. For some or all-of these reasons, the pipe section, as it advances along the mandrel, will be at a higher temperature at the advancing end where the axial compression forces are lower than they will be at the rear end where the resistance to endwise movement is greatest. The endwise forcing action is stopped when the rear end of the pipe reaches the inclined surface of the treme end portion of the swaged fitting is not of substantially the same thickness as the body portion, it may be trimmed oil. The ends may then be beveled to form the concentric reducer fittin shown in Fig. 1, or may be cut obliquely at the ends and beveled to form the eccentric reducer fitting of Fig. 3.

It will be understood that the means for supporting the inandrel, heating the pipe sections, and effecting relative endwise movement of the mandrel and pipe section to eflect the swaging action, are only conventionally illustrated as these parts may be of a wide variety of forms.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The process of forming a reducer fitting of frusto-conical form from a cylindrical pipe section of greater length, which includes applying pressure in an axial direction to an end of the cylindrical pipe section to force it from the smaller end towards the larger end of a frusto-conical mandrel, thereby progressively expanding the pipe section from cylindrical to conical form, simultaneously shortening it' due to the resistance of the frictional engagement between the pipe section and the mandrel surface, and maintaining the wall thickness substantially uniform.

2. The process of forming a reducer fitting of frusto-conical form from a cylindrical pipe section of greater length, which includes applying pressure in an axial direction to one end of the cylindrical pipe section to force it from the smaller end towards the larger end of a frusto-conical mandrel, thereby progressively expanding the pipe section from cylindrical to'conical form, simultaneously shortening it due to the resistance of the frictional engagement between the pipe section and the mandrel surface, heating the pipe section, and controlling the rate of endwise movement and the temperature to maintain the wall thickness of the resultant fitting substantially equal to that of the original pipe section.

3. The process of forming a frusto-conical pipe fitting from a cylindrical pipe section, which includes causing endwise movement of a frusto-,

RUDOLPH E. nrrscn.